1. Field of the Invention
This invention relates to a method and an apparatus for ranking broadcast programs in accordance with the preferences of a user of a television receiver.
2. Description of the Related Art
Many television programs are provided by BS broadcasting, CS broadcasting, and digital broadcasting. A user of a television receiver can select one from the television programs. As the number of broadcasted programs increases, it is more difficult for the user to comprehensively grasp what programs are being broadcasted. When broadcasted programs are so many, the user has some trouble in finding favorite one. In addition, there is a greater chance that the user may be unaware of the broadcasting of a favorite program and miss it.
Some television stations multiplex auxiliary program information with main television signals in order to help users of television receivers to select desired ones from many broadcast programs represented by the main television signals. The auxiliary program information represents the title, the on-air time, the on-air channel, the genre, the outline, and the performer list of each broadcast program.
Some television receivers employ the auxiliary program information to form electronic program guides. The displays of the television receivers indicate the electronic program guides to help users' choices of broadcast programs.
An advanced television receiver automatically generates a signal representing a history about the broadcast programs viewed by the user. The history signal includes the auxiliary program information concerning the viewed broadcast programs. The history signal is stored in a memory within the television receiver, and is updated from time to time. In the television receiver, the history signal is analyzed to decide user's preference (user's taste) in broadcast programs or what types of broadcast programs the user is interested in. The television receiver obtains auxiliary program information about forthcoming broadcast programs in advance. In the television receiver, the degrees of user's preference for the forthcoming broadcast programs are calculated from the obtained auxiliary program information and the results of the decision about the user's preference. The television receiver automatically selects ones, which may be preferred by the user, from the forthcoming broadcast programs according to the calculated degrees of user's preference.
Japanese patent application publication number 10-243309/1998 discloses a television channel selecting apparatus including a tuner and a demodulator. The demodulator separates each television signal received and selected by the tuner into a broadcast program and auxiliary program information representing a brief explanation of the contents of the broadcast program. For each broadcast program, a program evaluating section extracts keywords from the corresponding auxiliary program information. Then, the program evaluating section reads out the degrees of suitability of the extracted keywords for a viewer from a filtering-parameter storing and updating section. Subsequently, the program evaluating section calculates the sum of the read-out degrees of suitability as an indication of an evaluation value for the broadcast program. These steps are executed for each of viewable channels so that the evaluation values for the broadcast programs on the respective channels are obtained. The channels are ranked in accordance with the obtained evaluation values. Specifically, a program presenting section makes the images of the respective channels into a texture, and pastes the texture in a three-dimensional space while placing the broadcast program of a high evaluation value on the fore side.
In the apparatus of Japanese application 10-243309/1998, the filtering-parameter storing and updating section holds a list of predetermined keywords and the degrees of suitability of the predetermined keywords for a user. The extracted keywords are collated with the predetermined keywords to find ones of the predetermined keywords which match the extracted keywords. The degrees of suitability of the matching keywords are used as those of the extracted keywords. The degree of suitability varies from keyword to keyword. In addition, the degree of suitability of at least one of the predetermined keywords can be updated depending on the length of time during which the user continues to select a broadcast program corresponding to auxiliary program information having a keyword matching the predetermined keyword. Furthermore, the list of predetermined keywords depends on whether the user is a father, a mother, or a child.
In the apparatus of Japanese application 10-243309/1998, the updating of the degrees of suitability of the predetermined keywords does not consider how much the user concentrates on viewing related broadcast programs. Even conditions where a broadcast program remains selected for a long time while the user continues to read a book are considered in the updating of the degrees of suitability of related keywords. This fact causes a decrease in the reliability of the ranking of the channels.
Japanese patent application publication number 8-180504/1996 discloses a broadcast receiving apparatus designed to induce a user to watch a regular broadcast program usually accessed by the user. The broadcast receiving apparatus generates channel history information representing conditions of user's selection of program-corresponding channels as a function of a day of week and the time of day for a prescribed number of weeks up to the last week. The generated channel history information is stored in a memory, and is updated from time to time. The channel history information in the memory is searched for a channel corresponding to a user's favorite program, that is, a weekly broadcast program selected by the user at higher than a threshold frequency. In the case where such a channel is present, a received broadcast signal of the channel is automatically recorded on a recording medium at the scheduled time. Therefore, even when the user has missed the user's favorite program corresponding to the channel, it is possible to reproduce the user's favorite program from the recording medium.